Is it possible to lose the First Level of integrity in the aircraft?

The correct answer emphasizes that the First Level of integrity for the aircraft systems should always be maintained as long as there is a power source available. This principle is foundational for aircraft safety and reliability, particularly in modern avionics and control systems. The First Level of integrity is a safety measure designed to ensure that essential systems remain operational even in the case of a partial failure.

If the aircraft's systems are powered and functioning correctly, it is engineered to maintain its First Level of integrity during normal operations and specific failure scenarios. This ensures that critical functions and monitoring systems are continuously available to support safe flight operations and decision-making.

In scenarios such as engine failure or when the main bus goes down, while those events pose significant challenges, measures are in place to ensure that the First Level of integrity can be sustained through backup systems or alternative power sources, if available. The assertion that this level of integrity should always be powered speaks to the design philosophy that prioritizes safety and redundancy in the Pilatus PC-12 NG.